Originally Posted by boomn29

The goal is to take your vehicle, pick a class, pick a mix of mods using the allowed points and compete for the single fastest lap of the day. It's that simple. NASA TT runs with the unlimited open passing rules, meaning you can pass anyone anywhere at anytime (provided it's a safe clean pass, etc). So you have the potential of going 2-wide through corners, running 2ft off someones bumper or maybe not seeing any traffic for several laps! It all depends on the track, the session, and your grid position (front-to-back) on the entire group.
Naturally not all cars are competitive in every class and certain cars can be 'ringers' in certain classes. But most cars have a sweet spot in a certain class or 2. What are those classes?

From the slowest to the fastest:

• TTF - slow....
• TTE - Think Civic SI, Spec Miata
• TTD - Think e30 M3, ITR, late 90's Mustangs
• TTC - Think S2000, SRT4, Cobalt SS, e36 M3
• TTB - Think M3, stockish Evo/STi, Mustangs, , e36 M3
• TTA - Think C5 Vettes, Evo/STi, M3, S4
• TTS - 8.7:1 power/weight ratio class. Think Corvettes, Audi, Mustangs, GT3, e46 M3, modded Evo's and STI's
• TTU - 5.5:1 power/weight ratio class. Think Vipers, Z06's, Ferrari
• TTR - completely unlimited.

So TTA-TTF are the normal classes. Normal meaning they have to count their mod points. TTS-TTU simply have to hit the legal power/weight ratio and TTR is anything goes. Needless to say, the last 3 classes can get really expensive as there's no limit to the type of engine mods or fancy 4-way remote suspension or aero - the 3 more expensive avenues!

New for 2009, each class has been assigned a minimum “Adjusted” Weight/Power ratio. Regardless of how many points a car has, or which base class it begins in, it may not exceed the minimum “Adjusted” Weight/Power ratio for its competition class. Any vehicle found competing with an “Adjusted” Weight/Power ratio less than the minimum level assigned below will be disqualified.

NASA TT Official website: http://www.nasa-tt.com/

There's some strategy involved in NASA TT. Technically you could go out and turn 1 single flying lap and win for the day. Or you could be in last place all day making changes little by little and turn the winning lap in the final session to come from behind. There's also external factors that can screw up a good strategy like changing weather conditions, lap traffic, broken parts, scheduling issues, not making your base weight or even filling out your classification forms improperly!

The new for 2009 class power/weight ratio limits:

• TTR --> with unlimited power/weight & mods
• TTU 5.50:1 --> with unlimited mods
• TTS 8.70:1 --> with unlimited mods
• TTA 8.70:1
• TTB 10.25:1
• TTC 12.00:1
• TTD 14.25:1
• TTE 16.50:1
• TTF 19.50:1

As I mentioned, every car gets a base class and weight. From there they pick/choose the best mods possible to MAX the car out for the class. However, you do have the option to UPclass or DOWNclass depending on what type and how many mods you do.

Up-Classing System (TTA-TTF only)
Modifications and Point Assessments:
If your car accrues 20 or more points you will be bumped up in Class. There is no limit - a car
with a high level of modifications might move up several Classes.One (1) asterisk * on a base class assignment denotes a 7 point initial assessment, and two
(2) asterisks ** denotes a 14 point initial assessment that is added to the total number of
modification points to determine the final competition class.

So how are the different Evo models base classed and what are their base weights? See below. My car is bolded.

Originally Posted by projectmarzen

I'd like to know more about this, I am planning on doing some TT/TA next year, and I'll take the aero crap off if i can get some points back, also would be great to get some of the suspension points back too with my aftermarket coil-overs on.

Originally Posted by projectmarzen

I have been reading offline, we have this guy here in colorado that fits in TTA with his fully prepped e36 m3 race car, he shows up runs 1 session and dominates the entire tta class by a few seconds, takes the tires and leaves. I really dont feel like working in that sort of enviroment.

Originally Posted by JDavenport

Bottom line, there are just certain makes/models that hit very sweet spots in the NASA classing system. Nate has shown that with LOTS of testing, trial and error, the combination of points and driver can be used to field a competitive TTA Evo IX. But the class was almost made for C5Z Vette's who have to do a great deal less work than us (mod wise) to run at the front in TTA.

I have friends that run AP1 S2K's in TTC and they are starting to clean up at NASA events. The combination of where the car starts and how it responds to certain mod points yields a potent TTC setup.

I'm just going to go straight to TTS myself and have already entered my first TT event as such. I won't be competitive for a while, but TTS let's you level the field a little easier (albeit at a higher cost) against the C5Z's and things like race prepped e36's.

But Nate has shown that an Evo IX can run at the front in TTB and TTA. His posts and his racing blog are a wealth of information on the subject.

And I also agree, the MR gets hosed on points.

Originally Posted by Balrok

The way I read it, it falls under number 5:

5) Changed or modified limited slip differential (or welded/locked OEM LSD) +1

So with this one rule you could do the ACD flash and 12 plate as I understand it.

However they may be forcing us to take the +3, see what boom says. I'd design based on the +3 for now. Also i'd wait on the 2012 rules to see what changes come about.

Originally Posted by boomn29

I think you could reflash the ACD for free personally. You can reflash the ECU for free after all.

I'm not one to look for gray areas; but I don't see how they could check for it. Then again, there's really no way to verify an upgraded (aka TRE or Shep) rear diff other than taking it apart - but I'm taking the 1pt for modifying mine. My .02

Bottom line; +1 max imo.